264 
GELATINIZ ATION OF TINCTURE OF KINO. 
He says, 16 when the conversion of the real constituents of the 
plant into apotheme is yet incomplete, the material which 
dissolves equally in water and dilute alcohol, but not in abso- 
lute alcohol or in ether, is termed extractive." 
Now, in accordance with this definition, we may consider 
the kino or inspissated decoction of Nauclea Gambir, and the 
gelatinous tincture of kino, to be both products in which a 
change has been effected, first, from pure tannin to extractive, 
and then, from extractive to insoluble apotheme. or ulmic 
acid; only that, in the latter product, this change has been 
more complete than in the former. Thus it will be found 
that the insoluble residue of the kino, left after making the 
tincture, corresponds precisely with the gelatinous matter 
afterwards formed in the tincture. The partial conversion of 
the tannin into extractive and insoluble apotheme in the kino, 
has been effected by the action of the air and moisture, expe- 
dited by heat, during its inspissation. In the absence of 
moisture this change is suspended, and kino, if properly pre- 
served, will be found to contain these three constituents, 
tannic acid, extractive or altered tannin, and insoluble 
apotheme, or ulmic acid. In the preparation of the tincture, 
the tannic acid and extractive are taken up by the alcohol, 
and the conditions essential to the progress of the change be- 
ing now again present, the transition of the tannin into ulmic 
acid is gradually completed; giving rise to the gelatinous tinc- 
ture under consideration. 
The most effectual means of preventing this change would 
probably be, in preparing the tincture, to extract as speedily 
as possible the most soluble part of the kino, without allowing 
the solution, thus formed, to remain long in contact with the 
altered and less soluble constituents. It is well known that 
organic matter in a state of transformation acts as a kind of 
ferment in promoting a similar change in those bodies with 
which it may be in contact; and with a substance so suscep- 
tible of change as tannic acid, the influence thus exercised 
would, no doubt, be very decided. In confirmation of this, 
it will be found that tincture of kino made by the process of 
